Starters in Role of Architect

Would you please suggest How to become a good architect?
Especially if he has just started his new role with some experience in building enterprise level components in past.

Everyone wants their applications to be scalable, reliable, and available. But when it is under design stage How an architect will analyse these factors?
In real, would only one architect decide all these?
What are the roles of other departments in build these type of larger systems? (ex: System administrator : provides Hardware supports, Business Analysts: Who decides Who all their users for that system etc)

Is it must to get update with latest technology and trends to become success in architect?
If YES, how do they analyse incorporating these new technologies would make their system Great? as they may be new in industry, do architects create "Proof of Concepts" before injecting them into actual system??